Multiple lift elevating truck



D. E. HEN'NESSY MULTIPLE LIFT ELEVATING TRUCK April 4, 1939.

5 Sheets-Shed l Filed June 1, 1936 lrwenTor. Daniel E.Henness WW &/

April '4, 1939 D. E. HE NNESSY I MULTIPLE LIFT ELEVATING TRUCK 5 Sheets-Sheet 2 Filed June 1, 1936 lnvenTor. Dcmiel E. Henne ssy b /mzMe f April 4, 1939. D. E. HENNESSY MULTIPLE LIFT ELEVATING TRUCK Filed June 1, 1936 5 Sheets-Sheet 3 Y .N s 1 RS A m; W Z, E m HM 0 DV/ b April 4, 1939.-

D. E. HENNESSY 2,152,850

MULTIPLE LIFT ELEVATING TRUCK 5 Sheets-Sheet 4 Filed June 1, 1956 lnvenTor. Donlel E.Hennessy April 4, 1939.

D. E. HENNESSY 2,152,850

MULTIPLE LIFT ELEV ATING TRUCK Filed June 1, 1936 5 Sheets-Sheet 5 InvenTor. Daniel E. Hennessy byw ATTys.

Patented Apr. 4, 1939 UNITED STATES MULTIPLE LIFT ELEVATING TRUCK Daniel E. Hennessy, Petersham, Mass, assignor to Lewis-Shepard Company, Watertown, Mass, a corporation of Massachusetts Application June 1, 1936, Serial No. 82,757

22 Claims.

This invention relates to improvements in elevating trucks and the principal object of the invention is to provide an elevating truck of novel and relatively simple construction in which the load supporting means is raised step by step by power applied through a flexible member, a portion of which extends along the axis of the steering mechanism and is intermittently connected to and operated by vertical swinging movements of the tongue when in any steering position, with means to lock the load supporting means at each step of elevation.

Another object of the invention is to provide an elevating truck in which the lifting of the load supporting means and the release of the means for locking the load supporting means in elevated position are controlled by a single manually operated device carried by the tongue, thereby eliminating foot pedals and separate levers usually employed for controlling the lifting mechanism and the locking mechanism.

Another object of the invention is to provide novel means for avoiding a flying tongue and including means which will normally retain the tongue when in vertical position so that it will not fall down when released by the operator.

Another object of the invention is to provide a novel form of locking mechanism comprising a detent engaging the lifting member and adapted to move rearwardly with the lifting member as it is raised from engagement therewith.

Another object of the invention is to provide a double chain lifting mechanism with means selectively operable to raise the load supporting means a distance corresponding to lengths or half-lengths of the chain links.

These and other objects and features of the invention will more fully appear from the following description and the accompanying drawings, and will be particularly pointed out in the claims.

This application for patent upon improvements in Multiple lift elevating trucks is a companion of a co-pending application Serial No.

62,756 for improvements in Elevating trucks 1, also filed by me on June 1, 1936, and which discloses and broadly claims such features of the invention as are embodied in both single lift and multiple lift types of elevating trucks.

Preferred embodiments of the invention are shown in the accompanying drawings, in which,

Fig. l is a side elevation of the front portion of an. elevating truck embodying the invention, in which the load supporting means is lifted by a flem'ble member connected to a vertically swinging tongue, showing the load supporting means in lowered or loading position, the rear portion of the truck being broken away and certain portions of the handle mechanism being illustrated in section; I

Fig. 2 is a similar side elevation showing the load supporting means in elevated position and illustrating the position of the parts when the locking means is being released to permit the descent of the load supporting means;

Fig. 3 is a plan. view of the construction shown in Figs. 1 and 2;

Fig. 4 is a plan view of a modified construction in which a plurality of chains connect the load supporting means to the tongue;

Fig. 5 is a side elevation, partly broken away, of guiding sprockets for the chains and intermediate thereof a ratchet forming a part of the locking mechanism for retaining the load supporting means at each stepof elevation;

Fig. 6 is a view similar to that shown in Fig. 1, but in which a plurality of lifting chains are employed, the links of the chain being in staggered relation as illustrated in Fig. 7 and the tongue being provided with two pawls adapted alternatively to engage the links of the respective chains;

Fig. 7 is a detail plan view of the same showing two detents to engage the respective chains and adapted to lock the chains at each half-link step of elevation of the load supporting means;

Fig. 8 is a view similar to Fig. 1 showing a modified construction in which the lifting chains are actuated by a sprocket and pawl and ratchet mechanism operable by a vertical swinging forward movement of the tongue,

'Fig. 9 is a detail of the guiding sprocket or sprockets and the ratchet which is engaged by the locking detent in the construction shown in Fig. 8; and,

Fig. 10 is a plan view of the chain-actuating sprockets and of the ratchet located between said sprockets adapted to be engaged by a pawl on the vertically swinging tongue.

The preferred embodiment of the invention illustrated herein comprises a wheel-supported frame having side bars I and 2 connected at their front ends by a head comprising a flat plate 3 having downwardly extending flanges 4 and 5 which are connected, preferably by welding, to the side bars I and 2. Bearing members 6 and 1, which are preferably integral with the plate 3, extend upwardly from said plate at opposite sides of and symmetrically with the longitudinal axis of the truck, and are each preferably provided with forward extensions 8 and 9 offset to provide shoulders I along the front edges of the bearing members 6 and 1 adapted to form abutments for the rear ends of levers forming parts of the locking mechanism as will hereinafter more fully appear.

The head 3 is provided with a cylindrical forward extension II which forms the bearing of a vertical tubular steering post I2, the lower end of which is integral with a plate [3 which engages the under face of the extension and is provided with downwardly extending webs or forks M in the lower end of which a shaft I5 of one or more steering wheels [6 is mounted. The forks M of the steering mechanism are provided at their lower ends with forward extensions ll having mounted in the forward portions thereof a shaft l8 upon which is mounted the forked lower end of a tongue 19, a roller or drum 20, which is located between the forks of the tongue, being rotatably mounted upon the shaft Ill.

The load supporting means is in the form of a platform having side bars 2! which are connected at their front ends by a bridge member in the form of a horizontal plate 22 having an integral downwardly extending flange 23 along its rear edge and an upwardly extending vertical flange 24 along its forward edge. The ends of the flanges 23 are welded to the side bars 2 l. The load supporting means is mounted upon the frame by front and rear parallel links, of which the front links 25 alone are shown, the links 25 being pivotally mounted at their lower ends upon a shaft 26 which is mounted in the side members I and 2 of the frame, and the links are mounted at their upper ends upon a shaft 2! which is mounted at its ends upon the side bars 2| of the load supporting means. Desirably the load supporting means is wider than the frame and spacing sleeves 28 are interposed between the respective links 25 and the side bars 2| of the load supporting means.

The mechanism for lifting the load supporting means comprises one or more flexible members which are connected to the front end of the load supporting means and at the other end connected to and operable by vertical swinging movements of the tongue, with guiding means on the head located well above the load supporting means acting to direct the flexible member upwardly, thence downwardly along the vertical axis of the steering mechanism, with means upon the steering mechanism to guide the flexible member to the tongue so that successive vertical swinging movements of the tongue when in any steering position will pull the flexible member longitudinally and thereby raise the load supporting means step by step.

The tongue is pivotally mounted upon the lower portion of the steering mechanism in such proximity to the vertical axis thereof that when the flexible member is pulled longitudinally by the vertical swinging movements of the tongue, a substantially downwardly directed force will be exerted upon the vertical portion of the flexible member and will therefore not have a substantial tendency to tip the truck over when the tongue is moved from directly in front of the truck to a lateral steering position, thereby substantially avoiding the tendency to tip the truck over which is inherent in trucks heretofore produced in which the load supporting means is raised by downward swinging movements of the tongue when in lateral steering position.-

In the particular construction shown the flexible member comprises a chain 29 which is connected at its rear end to a lug or boss 30 extending forwardly from the vertical flange 24 of the load supporting means and which extends upwardly and is guided over a pulley or sprocket 3| having a shaft 32 which is mounted in the upper portion of the bearing members 6 and l. The chain preferably also passes over another guiding pulley 33, the shaft 34 of which is mounted in the extensions 8 and 9 of the bearing members 6 and 1 respectively. The guide 33 is so positioned as to direct the chain downwardly along the vertical axis of the steering mechanism. The chain preferably is made in two sections which are connected by a swivel which is located in the portion of the chain which extends vertically along the axis of the steering mechanism. In the particular construction illustrated the swivel comprises an upper cylindrical member 35 which slidably fits within the tubular steering post [2 and a lower swivel member 36 to which the upper end of the lower section 31 of the chain or flexible member is connected. A guiding pulley 3B, the shaft 39 of which is mounted in the forks M of the steering mechanism, is so positioned in cooperation with the guiding roller 33 as to maintain the central portion of the chain with the swivel therein along the vertical axis of the steering mechanism, and also serves to direct the lower portion of the chain around the drum 2%? which is mounted upon the shaft 18 upon which the tongue is pivoted. Desirably the lower end of the lower section of the chain has connected to it a take-up, such as a spring 40, the other end of which is connected to a stud or shaft 4! upon an arm or arms d2 preferably integral with and extending rearwardly from the fork or forks of the steering head.

The spring 49 serves to keep the lower section 37 of the chain under tension to insure engagement of the pawl 43 with the chain when the tongue is swung downwardly and also serves to maintain a proper relation between the links of the chain and the locking mechanism.

The tongue is provided with means operable selectively to engage or grip the chain or such other flexible member as may be substituted for the chain, so that the successive downward swin ing movements of the tongue will pull the chain or other flexible member lengthwise and thereby raise the load supporting means step by step.

In the preferred construction illustrated herein the means for thus gripping the chain comprises a long pawl 43, which is pivoted at its upper end upon a shaft 44 extending through the walls of the tongue and the lower end of which is adapted detachably to engage the chain and clamp it against the roller 20. The upper end of the pawl 43 preferably is provided with a rearward extension or latch 65 having a recess near its end forming a hooked end portion 46 adapted to engage the lock-releasing mechanism, as will hereinafter more fully appear. A rod 41 extends through a laterally projecting web or boss 48 on the latch 45 and is secured thereto against endwise movement by upper and lower cotter pins. or in any other desired manner. The rod 47 is offset at its lower end to engage the latch, but otherwise extends axially through the tongue, the upper section 49 of which is of tubular form. The upper end of the rod d! is provided with an enlarged head or button 56 to enable the rod to be forced lengthwise of the tongue to control the position of the pawl 43 and latch 45. The rod l! is normally forced upwardly by a spring 5! the lower end of which is seated upon a suitable abutawzsasso ment, such as a horizontal member 52 .of 2. Lushaped strap, :the legs 53 *of *which fit within the tubular tongue member andthe ends =54aof which are bent outwardly 'over the rend of the tubular tongue member. The upper end of the spring abuts againsta washer :55 held .by "a cotter pin 55 which passes through :therrodi'l.

The upper portion of the rod 4*! extends through a tubular handlezmember 51 which is secured upon lthe upper end of the tubular tongue member by :a fitting- 58, s,uch as a pipe .fitting 'of tubular form, fitting the :handle member and havingrside strapsor'extensions liil'which extends a substantial distance downwardly on opposite sides of the tubular end of the tongue and are welded thereto, Byreasonof this construction the ends 54 of the strap are firmly clamped between the fitting and the upper'end of the tubular tongue-49.

When the tongue :is in raised position the pawl is held in position to engage=a crossbar of one or more of the links of the flower chain section 31, so that a downward swinging movement of the tongue will cause the lower end of the pawl 43 to clamp the engaged link against the roller 20 and as the tongue is swung --downwardly will pull the chain lengthwise thereby lifting the load supporting means.

Suitable lockingmeans is provided-for retaining the load supporting means at each step of elevation. A preferred form of locking means, which is illustrated in Figs. :1, 2, and 3,.comprises a detent 60 having a hook-shaped end 6| to engage the transverse members of the links of the chain and a downwardly extending forked (portion 62, the lower ends .of which are ,pivotally mounted upon studs .63 the ends of which are mounted in the forward ends of triangular plates or levers '64 which are pivotally mounted upon the shaft 34 of the guiding roller 33. The rear ends of the plates desirably rarerrounded and adapted to engage the shoulders 10 f the bearing members 5, thereby to limit the clockwise movement of the levers or plates (64 to the ,position shown in Fig. 1. These triangulargplates or levers are normally retained in .such position by one or more springs 65, one endof "which is connected to a stud 66 upon the levenand the other end of which is connected toastud 61 upon an extension integral with and projecting rearwardly from the bearing member -6. The weight of the locking pawl or detent 60 is such that itsen'dfil will normally ride upon .the chain, so that as the chain is taken up 'by successive downward swinging movements of the tongue the hooked portion 6| of the detent will engage the transverse members of successive links. It therefore follows that by successive vertical movements of 'the tongue the load supportingmeans may be .raised step by step to its maximum elevation and will be locked at each step of elevation.

When the load supporting means is locked in raised position the tongue may be raised and the button 58 upon the controlling rod 41 .pressed downwardly to release the pawl 43 from its engagement with the link of the chain, thereby freeing the tongue for steering and also releasing the chain so that it may slacken and permit the descent of the load supporting means when the detent (it is released from looking engagement with the chain. One of the features of the invention consists in providing means operable by a vertical swinging movement of the tongue to release the locking mechanism. In the construcr tion illustrated the lock-releasing mechanism comprises awoke-shaped member formed of links .618 which are pivotally connected to the rear ends of the triangular plates or levers 64 and are connected at their forward ends to a cross bar 69 adapted to be held in a position in which it may be engaged by a hooked end 46 of the latch 45. In the particular construction shown the shaft 69 rests upon the upper end of the cylindrical forward extension I l of the head in which the steering post is mounted.

When it is desired to release the load supporting means from its raised position, the tongue is :swung "to vertical position and the button 50 at the end of the rod 4'! depressed, thereby swinging the hooked end 16 of the latch 45 into engagement with the cross bar 69. When thus engaged the tongue is swung downwardly thereby drawing the links of the yoke-shaped member forwardly, (as illustrated in Fig. 2), thus swinging the triangular levers 64 about the shaft 34 and raising theforward portion of the detent 60 and also moving it rearwardly.

The forward extension 8 of the bearing member '6 is provided with a preferably integral upward-1y extending plate 1|] having an upwardly and rearwardly inclined edge 1| adapted to be engaged by a stud l2 projecting laterally from the detent 69. When therefore the detent is moved upwardly and rearwardly, as above described, the stud 12 will ride up the inclined surface "H and raise the hook-shaped end Bl of the detent out of engagement with the link of the chain which it engages, thereby releasing the chainand permitting the load supporting means to descend.

It is noted that when the latch 45 is depressed to engage the crossbar 653 of the detent-actuating :yo'ke, the pawl 43 will-be swung out of engagementwith the link of the lower chain section 31, so that the chain can move freely lengthwise to permit the descent of the load supporting means being only restrained in its movement by the take-up spring 40.

When the hook-shaped end of the latch 45 is thus engaged with the shaft 69 of the yoke, and the tongue swung downwardly, the rotation of the levers 64 .about the shaft 63 will first raise the forward end of the detent 60 and as the downward swinging movement of the tongue proceeds the detent will be carried rearwardly in the direction of movement of the chain as the load supporting means descends until the raising of the stud 12 by its movement along the inclined surface H finally releases the hook-shaped end 61 from engagement with the link of the chain, thereby providing a gradual release of the locking mechanism. In the present construction, as in usual types of elevating trucks, suitable means such as a dash pot (not shown) is provided for cushioning the descent of the load and the restraining action of the dash pot will have begun during the time that the detent is being released from the chain, thereby reducing the resistance to the release of the pawl which otherwise would occur.

Thespring 65 normally holds the rearward ends ofthe levers 64 in engagement with the edge E8 of the bearing'fi in such position that the hooked end of the pawl lies below a plane passing through the axes of the shaft 34 and studs 68 thereby causing the lever 64 and pawl 60 to provide a toggle look as shown in Fig. 1. When the levers are swung to detent-releasing position, as shown in Fig. 2, the spring is placed under greater tension so that the lever 64 will be swung to normal locking position when the tongue is raised or when the latch 45 is disengaged from the shaft 69.

By reason of the fact that the shaft 64 when in normal position rests upon the upper end of the forward extension ll of the head, the shaft 59 is in position to be engaged by the hookshaped end 46 of the latch 45 when the tongue is raised to vertical position. As a consequence the tongue may be raised to such vertical position and locked in such position by simply depressing the button 58 of the rod 64, thereby avoiding the dropping of the tongue which otherwise might leave it in an undesirable position.

In the operation of the device, assuming the load supporting means to be in lowered position and the tongue in vertical position, the button 58 at the end of the handle is depressed thus freeing the tongue, enabling the truck to be moved to any position and backed beneath the usual load supporting skid. The tongue is then raised to vertical position and the pawl 43 automatically engages one of the links of the chain clamping it against the drum or roller 20 so that upon downward swinging movement of the tongue the chain is pulled lengthwise and the load supporting means raised a step in which it is locked by the detent 68 engaging a link of the chain. By repeated swinging movements of the tongue the load supporting means may be raised to the desired height. Inasmuch as a portion of the chain extends along the vertical axis of the steering mechanism and has a swivel therein, the load may be raised in this manner with the tongue in any steering position.

The truck may then be hauled to any desired spot where it is desired to deposit the load. The tongue is then raised to vertical position and the button 58 depressed to cause the latch 45 to engage the horizontal shaft 69 of the lock-releasing mechanism. After such engagement the tongue is again swung downwardly thereby raising the detent 66 and forcing it rearwardly. During such rearward movement of the detent the pin 52 rides upwardly on the inclined surface H, thereby releasing the detent from engagement with the link and permitting the load supporting means to descend, and to deposit the skid in the selected place.

Such lifting mechanism may be employed to raise the load supporting means Whether the latter is connected to the frame by parallel links or supported upon the frame by wedges which wll raise the load supporting means during the longitudinal movement thereof relatively to the truck, or it may be supported upon toggle mechanism or other mechanism which will permit the load supporting means to be raised vertically.

A modified form of the invention is illustrated in Figs. and 5 in which a plurality, preferably two chains i3 and T4 are pivotally connected to bosses 75 and '56 extending forwardly from the vertical flange 24 of the load supporting means. These chains pass over sprocket wheels 1'! and "it, the shaft 79 of which is mounted upon the upwardly extending bearing members 6 and l of the head. The bearing members may likewise be provided with forward extensions 8 and 9 having guding means mounted therein to direct the chains vertically downwardly in parallelism and in proximity to the axis of the steering mechanism. The chains desirably are made in sections and the ends of the upper sections connected to a swivel 88 of the character above described, the lower sections 8| and 82 of the chain, which extend downwardly from the swivel, being directed by guide rollers or sprockets 38 to the roller or drum 28 which is mounted coaxially with the pivot of the tongue. The tongue may be provided with a plurality of pawls like the pawl 43 to engage the respective chains and to actuate the same upon the vertical swinging movement of the tongue in a like manner, thereby to raise the load supporting means.

In this construction different locking means may be employed. In the construction illustrated a ratchet 83 is interposed between the sprocket wheels 11 and 18, which guide the respective chains, and is fixedly secured thereto preferably by a plurality of bolts or studs 84 passing through the sprocket wheels and the ratchet which is therebetween. The locking mechanism comprises a detent 85 having a hook-shaped end adapted to engage the teeth of the ratchet and the forward end of the detent is provided with laterally and downwardly extending arms 86 and 81 which are pivotally connected to the levers 64 which are mounted upon the shaft 34 of the forward guide roll or rolls 33 as heretofore described.

The mechanism for actuating the levers to release the detent 85 from the ratchet 83 may be and preferably is the same as that heretofore described comprising the links 68 which are pivotally connected at one end to studs on the levers 64 and at the other ends to the shaft 69 which is adapted to be engaged by the hook-shaped end 46 of the latch 45 when the tongue is raised to vertical position and the button 58 depressed, as heretofore described. Inasmuch as the same detent-releasing mechanism is employed in the construction shown in Fig. 4 as that shown in Figs. 1, 2, and 3, and heretofore described, detail illustration of it is omitted in the interest of clearness.

In this construction the detent 85 is provided with a laterally extending arm or stud 88 adapted to engage the inclined surface H of the plate 18 which projects upwardly from the extension 8 of the bearing member 6, so that when the latch 46 is depressed to engage the shaft 69 of the yoke which is connected to the levers 64 and the tongue swung forwardly, the levers will be rotated in a direction to raise the detent 85 and move it rearwardly and thereby impose the weight of the load upon the dash pot mechanism as the latch is raised out of engagement with the chain by the riding of the pin 12 upwardly along the inclined surface H of the plate 10.

The use of a plurality of chains may be desirable where the truck is adapted for heavy duty.

Another modification of the invention, in which double chain lifting members are employed, is illustrated in Figs. 6 and '7, and the object of this construction is to provide means by which short forward swinging movements of the tongue from its vertical position may be employed to raise the load supporting means and lock the same at each step or half-step of elevation. Such short forward swinging movement of the tongue is sometimes desirable particularly where a narrow aisle will prevent a usual downward swinging movement of the tongue. It also enables the operator to place his foot against the end of the truck to prevent forward movement of the truck during the lifting operation and in addition enables the operator to raise the load supporting means without any substantial bending of the body as would be required by a longer downward movement of the tongue.

The truck in general construction is the same as heretofore described as indicated by the numerals upon the drawings and need not therefore be described in detail. A novel feature of this construction comprises the employment of two chains in which the links of the chains are in staggered relation to each other with means operable by the forward swinging movement of the tongue to engage alternately the links of the different chains, with locking means acting respectively upon said chains to lock the load supporting means in shorter or half steps of elevation.

In this construction lifting chains 89 and 99 are connected to bosses 9| and 92 extending forwardly from the vertical flange 24 of the load supporting means and the end link 93 of the chain 99 is sufficiently longer than the corresponding end link of the chain 89 so that the pins, which connect the links of the chain 99, will lie opposite the centers of the corresponding links of the chain 89, or in other words the links are staggered one-half a step relatively to each other. The chains 89 and 99 pass upwardly over suitable guiding means which direct the chain vertically downwardly along the axis of the steering mechanism and are connected to a swivel 94 reciprocably mounted in the tubular steering post I2 and other lower chain sections 95 and 99 which are connected to the lower section of the swivel are guided axially of the steering post and thence over the drum 29 and are connected to take-up springs 49 of the character heretofore described.

The tongue I9 is provided with a forked lower end which is pivotally mounted upon the drum shaft I9 as above described, but is provided with two chain-actuating pawls instead of one. One of these actuating pawls may be and preferably is identical with the pawl 43 heretofore described which is pivoted at its upper end upon the shaft 94 mounted in the tongue and is provided with a lateral extension or latch 45 having near its end and recesses 46 to engage the lock-releasing mechansim.

The other pawl 91 is rotatably mounted at its upper end upon the shaft 44 so that it may swing freely. The pawl 43 has secured to it a bar 98, or other suitable means, which extends across the rearward edge of the pawl 97 so that when the lower end of the pawl 43 is swung forwardly the bar 98 will engage the pawl 91 and swing it out of operative relation to the links of the chain 96.

When the tongue is swung to substantially vertical position one of the pawls 43 or 91 will be swung by gravity, or by the action of the spring 5! upon the rod 41 which is connected to the extension 45 of the pawl 43, into engagement with the link of its chain so that upon forward swinging movement of the tongue the engaged chain will be clamped against the drum 29 and during the forward movement of the tongue will pull its chain, the swivel and the upper section of both chains longitudinally thereby raising the load supporting means. If the forward swinging movement of the tongue is insufficient to draw the chain upon the drum the full length of the link, the next rearward movement of the tongue will cause the other pawl to engage a link of its chain and upon the next forward swinging movement of the tongue lengthwise pull will be exerted through its chain to raise the load supporting means another half step. Of course the tongue may be swung through such an are as to pull eitherchain a distance equal to a link and onehalf, two links and one-half, etc., but in each case the next rearward movement of the tongue will cause one of the pawls to engage a link of its chain. By reason of this construction the operator can select such movement of the tongue as may be most advantageous to him, means being provided, of course, to lock the load supporting means against descent whenever the tongue is swung rearwardly.

In order to provide for the locking of the load supporting means at each half-step of elevation independently operable detents are provided to engage the respective chains. Desirably means, adapted to be actuated by a forward swinging movement of the tongue such as heretofore described, are provided for simultaneously actuating both detents in such manner as to release the engagement of either of them with its chain when it is desired to lower the load supporting means.

In the construction illustrated in Fig. 6 two L-shaped detents 99 and I99 are provided, the vertical legs of such detents being pivotally mounted upon the studs 63 of the triangular shaped plates or levers 64. The horizontal arms of these detents are provided with hook-shaped ends WI and I02 adapted to engage the links of the respective chains 89 and 99. The detent 99 is provided with a laterally extending stud 12 adapted to engage and ride upon the inclined edge II of the upwardly projecting plate I9 and the detent I99 is provided with a laterally extending stud 12:1: adapted to ride up on the similarly inclined surface of a corresponding plate 190: formed integral with and extending upwardly from the bearing member I. The triangular levers or plates 64 are actuated by a link 68 connected at their front ends by a shaft 69 adapted to be engaged by the recesses 46 in the latch 45 when the tongue is raised to vertical position and the rod 41 depressed by the head 69 which projects beyond the handle.

The operation of the detent-releasing mechanism is therefore similar to that previously described for when the tongue is swung to vertical position and the latch 45 depressed and its recess engaged with the shaft 69, the forward swinging movement of the tongue will rotate the levers 46 about their shaft 34, thereby first raising the vertical legs of the pawls 99 and I99, then forcing them rearwardly so that the studs I2 and 12a: will ride upwardly on the inclined surface on the plates "I9 and 19:11, thereby releasing the engagement of the detent 99 or I99 with its chain. Such rearward movement of the detents enables the weight of the load supporting means to be placed upon the dash pot (not shown), before disengagement of the hooked end of the detent with its chain, is eifected, so that the detent is easily disengaged from the chain. I

Another modification of the invention which may be applied either to a single or plural-chain lifting mechanism is illustrated in Figs. 8 and 9 of the drawings. In this embodiment of the invention the elevating truck is of the same general construction but the chain or chains is or are guided over upper sprocket wheels, thence downwardly along the axis of the steering mechanism and thereafter guided over a sprocket or sprockets which are fixedly secured to the shaft upon which the tongue is pivotally mounted. This sprocket is actuated by means of a ratchet connected to said shaft or to the sprocket and rotated by a pawl pivotally mounted upon the tongue. The locking mechanism comprises a ratchet which is secured to or integral with the guiding sprocket or sprockets over which the chains pass with a suitable detent to engage the locking ratchet.

In the constructions illustrated in Figs. 8 and 9 the chain or chains I03, which are connected to the front end of the load supporting means, extend upwardly and are guided over a sprocket or sprockets I04, thence over the guide roll 33 to the upper section I05 of a swivel which is mounted to reciprocate along the axis of the steering post. The lower section I06 of the chain or chains, which is connected to the other member of the swivel, is guided axially of the steering post by the guide roll 39 and thence over a sprocket or sprockets I01 which are fixedly secured to the shaft I08 upon which the tongue I9 is pivotally mounted.

A ratchet I09 is fixedly secured to the shaft I08 or to the sprocket I01 (if the latter is rotatably mounted on the shaft) and is adapted to be engaged by a pawl IIO having a properly shaped lower end III to engage the teeth of the ratchet I09. The pawl H is mounted upon the shaft 44 and has a rearwardly extending latch 45 provided with a recess 46 like that hereto-fore described for engaging the lock-releasing mechanism. The'lock-releasing mechanism comprises an L-shaped detent II2 similar to the detent 60 shown in Fig. 1 and provided with a hook-shaped end I I3.

The hooked end II3 of the detent is positioned to engage the teeth of a ratchet I I4 secured to the sprocket I04, or if a plurality of sprockets I04 are provided, as illustrated in Fig. 9, the locking ratchet II4 may be conveniently located between the sprockets I04 and clamped thereto by suitable bolts II5 extending through the sprockets and the ratchet therebetween.

In the construction shown in Fig. 9 the locking ratchet H4 is provided with closely arranged teeth of considerably greater number than the number of teeth of the sprockets to provide suitable locking mechanism for short forward movements of the tongue as well as for the more extended or full swinging movements thereof.

In this construction, as in those previously described, the detent H2 is released from engagement with the locking ratchet H4 by raising the tongue to vertical position, depressing the latch 45 into engagement with the bar 69 so that when the tongue is swung forwardly the links 08 will be pulled forwardly thus. rocking the triangular levers 64 about their axes, thereby raising the detent [I2 and forcing it rearwardly until the hooked end II3 of the detent is disengaged from the teeth of the locking ratchet I I4.

It will be understood that the selected embodiments of the invention shown and described herein are of an illustrative character and that various changes in form, construction and arrangement of parts may be made within the meaning and scope of the claims; for example, other flexible members, such as cables or the like may be employed with suitable gripping mechanism operable by vertical swinging movements of the tongue to pull the flexible lifting means lengthwise, and other types of locking mechanisms and means for actuating the same may also be employed to cooperate with the lifting mechanism.

Having thus described the invention, what is claimed as new, and desired to be secured by Letters Patent, is:

1. An elevating truck comprising load supporting means, steering mechanism having a hollow 5 steering post rotatableabout a vertical axis and a tongue mounted thereon to swing vertically, a flexible member connected to said load supporting means, means for guiding a portion of said flexible member upwardly thence downwardly through said hollow steering post, means mounted on the lower portion of said steering mechanism operable in cooperation with vertical swinging movements of said tongue to move said flexible member longitudinally step by step and thereby elevate said load supporting means, and means for locking said load supporting means at each step of elevation.

2. An elevating truck comprising load supporting means, steering mechanism having a hollow steering post rotatable about a vertical axis and a tongue mounted thereon to swing vertically, a flexible member connected to said load supporting means, means for guiding a portion of said flexible member upwardly thence downwardly through said hollow steering post, means mounted on the lower portion of said steering mechanism selectively operable by vertical swinging movements of said tongue repeatedly to grip said flexible member and pull the same longitudinally thereby to raise the load supporting means step by step, and means for locking said load supporting means at each step of elevation.

3. An elevating truck comprising load supporting means, steering mechanism having a hollow steering post rotatable about a vertical axis and a tongue mounted thereon to swing vertically, a flexible member connected to said load supporting means, means for guiding a portion of said flexible member upwardly thence downwardly through said hollow steering post, means for pulling said flexible member longitudinally to raise said load supporting means comprising a drum rotatably mounted on the lower portion of said steering mechanism, and means on said tongue cooperating with said drum operable by repeated vertical swinging movements of said tongue to raise said load supporting means step by step, and means for locking said load supporting means at each step of elevation.

l. An elevating truck comprising load supporting means, steering mechanism having a hollow steering post rotatable about a vertical axis and a tongue mounted thereon to swing vertically, a flexible member connected to said load supporting means, means for guiding a portion of said flexible member upwardly thence downwardly through said hollow steering post, means for pulling said flexible member longitudinally to raise said load supporting means comprising a drum rotatably mounted on the lower portion of said steering mechanism coaxially with the pivot of said tongue, and means on said tongue operable to clamp said flexible means upon said drum and upon repeated vertical movements of said tongue to pull said flexible member longitudinally thereby to raise said load supporting means, and means for locking said load supporting means at each step of elevation.

5. An elevating truck comprising a wheel-supported frame having a head, steering mechanism having a vertical tubular steering post rotatably mounted in said head and a tongue pivotally mounted on the lower portion of said steering mechanism to swing vertically, load supporting means mounted on said frame by means operable upon longitudinal movement of said load supporting means relatively to said frame to raise said load suporting means, a chain connected to the front end of said load supporting means,

guiding means on said head located well above said load supporting means and operable to direct a portion of said chain vertically downwardly through said tubular steering post and thence to said tongue, means operable by vertical swinging movements of said tongue successively to grip predetermined links of said chain upon downward swinging movements of said tongue, thereby to pull said chain longitudinally to raise the load suporting means, and means for locking the load supporting means at each step of elevation.

6. An elevating truck comprising a wheel-sup ported frame having a head, steering mechanism having a vertical tubular steering post rotatably mounted in said head and a tongue pivotally mounted on said steering mechanism to swing vertically, load supporting means mounted on said frame by means operable upon longitudinal movement of said load supporting means relatively to said frame to raise said load supporting means, a chain connected tothe front end of said load supporting means, guiding means. on said head located well above said load supporting means and operable to direct a portion of said chain vertically downwardly through said tubular steering post and thence to said tongue, a swivel in said chain having a cylindrical portion reciprocable within said tubular post, means operable by vertical swinging movements of said tongue successively to grip predetermined links of said chain upon downward swinging movements of the tongue when in any steering position acting to pull said chain longitudinally to raise the load supporting means, and means for locking the load supporting means at each step of elevation,

'7. An elevating truck comprising a wheel-supported frame having a head, steering mechanism having a vertical hollow steering post rotatably mounted in said head, a tongue pivotally mounted on the lower portion of said steering mechanism to swing vertically, load supporting means mounted on said frame by means operable upon longitudinal movement of said load supporting means. relatively to said frame to raise said load supporting means, a drum mounted on said steering mechanism coaxially with the pivot of said tongue, a chain connected at one end to said load supporting means, means for guiding said chain upwardly thence downwardly through said hollow steering post and over said drum, a pawl pivotally mounted on said tongue acting when the tongue is in substantially vertical position to engage a link of said chain and upon downward swinging movement of said tongue to pull said chain longitudinally, thereby to raise the load supporting means, and means for locking said load supporting means at each step of elevation.

8. An elevating truck comprising a wheel-supported frame having a head, steering mechanism having a vertical hollow steering post rotatably mounted in said head, a tongue pivotally mounted on the lower portion of said steering mechanism to swing vertically, load supporting means mounted on said frame by means operable upon longitudinal movement of said load supporting means relatively to said frame to raise said load supporting means, a drum mounted on said steering mechanism coaxially with the pivot of said tongue, 'a chain connected at one end to said load supporting means, means for guiding said chain upwardly thence vertically downwardly through said hollow steering. post and over said drum, a swivel in the vertical portion of said chain, a pawl pivotallymounted on said tongue acting when the tongue is in substantially vertical position to engage a link of said chain and upon downward swinging movement of said tongue to pull said chain longitudinally, thereby to raise the load supporting means, means for locking said load supporting means at each step of elevation, and means for taking up the slack of the chain as it is drawn downwardly.

9. An elevating truck comprising a wheel-supported frame having a head, steering mechanism having a vertical hollow steering post rotatably mounted in said head, a tongue pivotally mounted on the lower portion of said steering mechanism to swing vertically, load supporting means mounted on said frame by means operable upon longitudinal movement of said load supporting means relatively to said frame to raise said load supporting means, a drum mounted on said steering mechanism coaxially with the pivot of said tongue, a chain connected at one end to said load supporting means, means for guiding said chain upwardly thence vertically downwardly through said hollow steering post and over said drum, a swivel in the vertical portion of said chain, a pawl pivotally mounted on said tongue, means for controlling said pawl comprising a rod connected to an oifset portion thereof and extending longitudinally through said tongue and provided beyond said tongue with a head, a spring normally acting to pull said rod upwardly and to force said pawl into engagement with the link of said chain and clamp the same upon said drum, whereby a downward swinging movement of said tongue will pull said chain longitudinally to raise the load supporting means and means for locking the load supporting means at each step of elevation.

10. An elevating truck comprising load supporting means, steering mechanism having a tongue mounted thereon to swing vertically, means operable by a vertical swinging movement of the tongue to lift said load supporting means, means for cushioning the descent of said load supporting means, movable locking means normally fixedly positioned to hold said load supporting means in elevated position, lock releasing means for moving said locking means in a direction to permit a limited downward movement of the load supporting means thereby to impose the weight of said load supporting means upon said cushioning means, means to disengage said locking means during said limited downward movement, and manually operable means for actuating said lock releasing means.

11. An elevating truck comprising load supporting means, steering mechanism having a tongue mounted thereon to swing vertically, means operable by a vertical swinging movement of the tongue to lift said load supporting means step by step, means for cushioning the descent of said load supporting means, means for locking the load supporting means at each step of elevation including a rearwardly movable locking detent normally fixedly positioned to engage a relatively movable complementary member of said lifting means and thereby to prevent downward movement of said load supporting means, lock releasing means for moving said pawl rearwardly to permit a limited downward movement of said load supporting means thereby to impose the weight of said load supporting means on said cushioning means, means operable during the rearward movement of said pawl to release it from engagement with said complementary members, and means on said tongue selectively movable into engagement with said lock releasing means when the tongue is in raised position and operable by a forward swinging movement of the tongue to actuate said lock releasing means.

12. An elevating truck comprising a wheelsupported frame having a head, steering mechanism having a vertical hollow steering post rotatably mounted in said head, a tongue pivotally mounted on the lower portion of said steering mechanism to swing vertically, load supporting means mounted on said frame by means operable upon longitudinal movement of said load supporting means relatively to said frame to raise said load supporting means, a chain connected at one end to said load supporting means, guiding means on said head located well above said load supporting means and directing said chain upwardly and thence downwardly through said hollow steering post, means operable by vertical swinging movements of said tongue to raise said load supporting means step by step, means for locking said load supporting means at each step of elevation comprising a detent mounted on said head having a hook-shaped end to engage a link in said chain, and means for lowering said load supporting means comprising means for moving said detent rearwardly, and means for removing said detent from looking engagement with said chain during the rearward movement thereof.

13. An elevating truck comprising a wheelsupported frame having a head, steering mechanism having a vertical hollow steering post rotatably mounted in said head, a tongue pivotally mounted on the lower portion of said steering mechanism to swing vertically, load supporting means mounted on said frame by means operable upon longitudinal movement of said load supporting means relatively to said frame to raise said load supporting means, a chain connected at one end to said load supporting means, guiding means on said head located well above said load supporting means and directing said chain upwardly and thence downwardly through said hollow steering post, means operable by vertical swinging movements of said tongue to raise said load supporting means step by step, means for locking said load supporting means at each step of elevation comprising a detent having a hook shaped end to engage a link in said chain, a lever pivotally connected to the other end of said detent, means normally holding said lever in position to cause engagement of said detent with a link of said chain as the chain is drawn forwardly, means for detachably connecting said lever to said tongue when the latter is in substantially vertical position operable upon downward swinging movement of said tongue to move said detent rearwardly, and means operable during the rearward movement of said detent to raise the hook-engaging end thereof out of engagement with said chain.

14. An elevating truck comprising a wheelsuported frame having a head, steering mechanism having a vertical hollow steering post rotatably mounted in said head, a tongue pivotally mounted on the lower portion of said steering mechanism to swing vertically, load supporting means mounted on said frame by means operable upon longitudinal movement of said load supporting means relatively to said frame to raise said load supporting means, a drum mounted on said steering mechanism coaxially with the pivot of said tongue, a chain connected at one end to said load supporting means,

means for guiding said chain upwardly thence vertically downwardly through said hollow steering post and over said drum, a swivel in the vertical portion of said chain, apawl pivotally mounted on said tongue, having at its upper end a rearwardly extending hook-shaped portion, means for controlling said pawl comprising a rod connected to the rearwardly extending end portion thereof and extending longitudinally through said tongue and provided beyond said tongue with a head, a spring normally acting to pull said rod upwardly and to force said pawl into engagement with the link of said chain and to clamp the same upon said drum, whereby downward swinging movement of said tongue will pull said chain longitudinally to raise the load supporting means, means for locking the load supporting means at each step of elevation comprising a detent having a hook-shaped end to engage a link in said chain, a lever pivotally connected to said detent, means for detachably connecting said lever to said tongue when the latter is in substantially vertical position operable upon downward swinging movement of said tongue to move said detent rearwardly, and means operable during the rearward movement of said detent to raise the hookengaging end thereof out of engagement with said chain.

15. An elevating truck comprising a wheelsupported frame having a head, steering mechanism having a hollow steering post mounted in said head to rotate about a vertical. axis and having a tongue mounted to swing vertically load supporting means mounted on said frame by means operable upon forward movement of the load supporting means relatively to said frame to raise said load supporting means, a flexible member connected to said load supporting means, means for guiding a portion of said flexible member upwardly thence downwardly through said hollow steering post, means on said tongue for gripping said flexible member and upon downward swinging movement of said tongue to pull said flexible member longitudinally thereby to raise said load supporting means, means for locking said load supporting means at each step of elevation comprising a detent positioned to engage said flexible member, and controlling mechanism carried by said tongue and operable selectively to cause said gripping means to engage said flexible member or to actuate mechanism for releasing said locking means.

16. An elevating truck comprising a wheelsupported frame having a head, steering mechanism having a vertical tubular steering post rotatably mounted in said head, including a tongue pivotally mounted on the lower portion of said steering mechanism to swing vertically, load supporting means mounted on said frame by means operable upon longitudinal movement of said load supporting means relatively to said frame to raise said load supporting means, a plurality of chains connected at like ends to said load supporting means, means including sprocket wheels rotatably mounted in said head engaging the respective chains, means on said head and steering mechanism for directing portions of said chains vertically through said tubular steering post, a swivel connecting the vertical portions of said chains, means operable by a downward swinging movement of said tongue to pull said chains lengthwise thereby to raise said load supporting means, and means for locking said load supporting means at each step of elevation.

17. An elevating truckcomprising a wheelsupported frame having a head, steering mechanism having a vertical tubular steering post rotatably mounted in said head, a tongue pivotally mounted on the lower portion of said steering mechanism to swing vertically, load supporting means mounted on said frame by means operable upon longitudinal movement of said load supporting means relatively to said frame to raise said load supporting 'means, a plurality of chains connected at like ends to said load supporting means, means, including sprocket wheels rotatably mounted in said head engaging the respective chains, and means on said head and steering mechanism for directing portions of said chains vertically downwardly through said hollow steering post, a swivel connecting the vertical portions of said chains, means operable by a downward swinging movement of said tongue to raise said load supporting means, and means for looking said load supporting means at each step of elevation comprising an actuating lever, a detent pivotally mounted on said actuating lever having a hook-shaped end engaging a ratchet fixedly secured to said sprocket wheels, means normally holding said actuating lever and detent in position to prevent retrograde movement of said ratchet, means for releasing said detent comprising means for rotating said actuating lever in a direction to permit retrograde movement of said ratchet, and means operable during such retrograde movement to raise said detent from engagement with the ratchet to permit completion of the descent of the load.

18. An elevating truck comprising a wheel-supported main frame having a head, steering mechanism having a vertical tubular steering post rotatably mounted in said head and having a tongue mounted to swing vertically, load supporting means mounted on said frame by means operable upon longitudinal movement of said load supporting means relatively to said frame to raise said load supporting means, a drum rotatably mounted on said steering mechanism coaxially with the pivot of said tongue, two chains connected at one end to said load supporting means with the links of one of said chains in staggered relation to those of the other chain, means for guiding said chains upwardly thence downwardly along the axis of said tubular steering post and over said drum, two pawls pivotally mounted on said tongue in cooperative relation to the respec tive chains and said drum, each pawl acting upon successive forward swinging movements of said tongue to engage a link of its chain alternatively with respect to the engagement of the other pawl with its chain and to pull its chain longitudinally, and means for locking said load supporting means against descent at each step of elevation.

19. An elevating truck comprising a wheel supported main frame having a head, steering mechanism having a vertical tubular steering post rotatably mounted in said head and having a tongue mounted to swing vertically, load supporting means mounted on said frame by means operable upon longitudinal movement of said load supporting means relatively to said frame to raise said load supporting means, a drum rotatably mounted on said steering mechanism coaxially with the pivot of said tongue, two chains connected at one end to said load supporting means with the links of one of said chains in staggered relation to those of the other chain, means for guiding said chains upwardly thence downwardly through said hollow steering post and over said drum, two pawls pivotally mounted on said tongue in cooperative relation to the respective chains and said drum, each pawl acting upon successive forward swinging movements of said tongue to engage a link of its chain alternatively with respect to the engagement of the other pawlwith its chain and to pull its chain longitudinally, locking detents positioned in cooperative relation to the respective chains, and means adapted to be connected to the tongue and operable by the forward swinging movement of said tongue to move both detents rearwardly and thereby to release the engaged detent from its chain.

20. An elevating truck comprising a wheelsupported main frame having a head, steering mechanism having a vertical tubular steering post mounted on said head and having a tongue mounted thereon to swing vertically, load supporting means mounted on said frame by means operable upon longitudinal movement of said load supporting means relatively to said frame to raise said load supporting means, a chain-actuating sprocket mounted on the lower portion of said steering mechanism, a chain connected at one end to said load supporting means, means for guiding said chain upwardly thence downwardly through said tubular steering post and over said chain-actuating sprocket, a ratchet rigidly secured to said sprocket, and a pawl mounted upon said tongue in cooperative relation to said ratchet operable upon forward movement of said tongue to pull said chain lengthwise and thereby raise the load supporting means, and means for locking the load supporting means at each step of elevation.

21. An elevating truck comprising a wheelsupported main frame having a head, steering mechanism having a vertical tubular steering post mounted on said head and having a tongue mounted thereon to swing vertically, load supporting means mounted on said frame by means operable upon longitudinal movement of said load supporting means relatively to said frame to raise said load supporting means, means for guiding said chain upwardly and thence downwardly through said tubular steering post including a guiding sprocket mounted on said head well above the plane of said load supporting means, a chain-actuating sprocket and ratchet mounted on the lower portion of said steering mechanism, a pawl on said tongue cooperating with said ratchet, and means for locking said load supporting means at each step of elevation including a locking ratchet fixedly secured to said guiding sprocket, a detent mounted in cooperative relation to said locking ratchet, and means selectively operable by the forward swinging movement of said tongue to move said detent rearwardly and also to release the same from said locking ratchet.

22. An elevating truck comprising a wheelsupported main frame having a head, steering mechanism having a vertical tubular steering post mounted on said head and having a tongue mounted thereon to swing vertically, load supporting means mounted on said frame by means operable upon longitudinal movement of said load supporting means relatively to said frame to raise said load supporting means, two chain-actuating sprockets rotatably mounted on said steering mechanism coaxially with the pivot of said tongue, two chains connected at one end to said load supporting means, means for guiding said chains upwardly and thence downwardly through said tubular steering post including sprockets engaging said chain said chain-actuating ratchet, and a detent positioned to engage the teeth on said locking ratchet for locking the load supporting means at each step of elevation, and means selectively operable by the forward swinging movement of said tongue to move said detent upwardly and rearwardly and to disengage the same from said locking ratchet.

DANIEL E. HENNESSY. 

